Micro-electro-mechanical system (MEMS) sensors are widely applied to vehicles, inertial guidance systems, home electrical appliances, protection systems for various apparatuses, and various industrial, scientific, and engineering systems.
Such a MEMS sensor senses a physical condition such as acceleration, pressure, temperature, etc., and provides an electrical signal corresponding to the sensed physical condition.
Many high performance MEMS sensors are packaged as a closed or sealed type in a vacuum or gaseous environment.
According to various MEMS sensor technologies, a sensing substrate wafer may be processed by a dicing process, and then a MEMS sensor substrate may be packaged and sealed as a closed type in a package level.
The method of packaging and sealing the MEMS sensor may include silicon to glass anodic bonding that uses various intermediate bonding agents, and a package level sealing (PLS) process including wafer-to-wafer bonding.
However, the package level sealing process may cause problems such as static friction between the sensing wafer and substrate components during the bonding process, or a low yield of the MEMS sensors.
In order to solve these problems and to reduce undesirable characteristics associated with the PLS, simple and rapid wafer level packaging (WLP) technologies are desirable.
The above information disclosed in this Background section is only to enhance the understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known.